1. Field of the Invention
The present invention relates to a torque wrench used for attachment and detachment of an ultrasonic vibrator and an ultrasonic probe, threadedly engaged with each other in an ultrasonic treatment instrument, and an ultrasonic surgical device.
2. Description of the Related Art
In general, an ultrasonic treatment device includes an ultrasonic vibrator, and an ultrasonic probe which transmits ultrasonic vibration output from the vibrator to a treatment section provided at the distal end of the treatment device. The ultrasonic vibrator and the probe are connected to each other by a threaded engagement portion. During use of the ultrasonic treatment device, the vibrator and the probe are attached to and detached from each other.
A tool that is used to attach/detach an ultrasonic vibrator and an ultrasonic probe to/from each other is disclosed in Japanese Patent No. 3276631. This tool includes a cylindrical member which applies torque to the probe of an ultrasonic treatment instrument, and an adapter used in combination with the cylindrical member. A ratchet-type torque adjustment mechanism that adjusts torque applied to the probe of the treatment instrument is provided between the cylindrical member and the adapter. The cylindrical member and the adapter are assembled together when the tool is operated to attach/detach the vibrator and probe to/from each other. In this state, the probe of the ultrasonic treatment instrument is passed through the cylindrical member, and the adapter is rotated around the axis of the probe so that the probe is screwed into the vibrator. As this is done, the torque applied to the probe of the treatment instrument is adjusted to a fixed value by the torque adjustment mechanism provided between the cylindrical member and the adapter.
A torque wrench that is used to attach/detach an ultrasonic vibrator and ultrasonic probe to/from each other is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2008-264994. This torque wrench includes an arm used as an operating section, a head portion, and an urging member such as a torsion coil spring. The head portion is pivotably mounted on the distal end of the arm and engages with an ultrasonic probe. The urging member is mounted on the arm and applies urging force to the head portion. A wrench receiving portion of the ultrasonic probe is introduced into an engaging recess of the head portion, and the head portion engages with the probe. The arm of the torque wrench is operated to apply torque to the probe with the head portion in engagement with the probe. By this tightening operation, the proximal end portion of the probe is screwed into and secured to the ultrasonic vibrator. If a preset value is exceeded by the torque thus applied to the wrench, the torsion coil spring contracts so that the head portion is pivoted around a pivot pin with respect to the arm as the operating section. Thus, the tightening torque on the ultrasonic probe can be adjusted to a fixed value during the tightening operation in which the proximal end portion of the probe is threadedly secured to the vibrator by the torque wrench.
A torque wrench described in Jpn. Pat. Appln. KOKAI Publication No. 2006-255803 is used to secure a probe of an ultrasonic surgical device to a vibrator with an appropriate torque. One part of this torque wrench is used to secure the probe to the vibrator, and another part of this torque wrench is used to remove them from each other.